The female MU figures are a good size for SW customs, and the new X-23 sculpt has a really good have the female TCW body habitus. Unfortunately, they're really tall. I've found if you pop off the thigh and cut about a half centimeter off, you get them to the size of Ventress or Aurra Sing.
I grabbed a couple of the MU Comic packs at $10 with the recent Target clearance. Juggernaut and Collossus are too big for anything but SW creatures like the Wampa, a Gundark or something from the Tartakovsky CW Arena, when we were introduced to Ventress. They were just too cheap to pass up.